Saint-Mesmin (French pronunciation: [sɛ̃ mɛmɛ̃]; Limousin: Sent Maimin) is a commune in the Dordogne department in Nouvelle-Aquitaine in southwestern France.

The commune is located in the north-east corner of the Dordogne department, on a hill above the river Auvézère.

The village is located 42 km (26 mi) north-east of Périgueux.

Three years later in 1793 it joined the Dordogne department.

Since World War I, the population has gradually been declining until it reached its lowest point in 2009.